The Netfilter development team's Patrick McHardy has released an alpha version of nftables, a new firewall implementation for the Linux kernel, with a user space tool for controlling the firewall. nftables introduces a fundamental distinction between the user space defined rules and network objects in the kernel: the kernel component works with generic data such as IP addresses, ports and protocols and provides some generic operations for comparing the values of a packet with constants or for discarding a packet.